10 examples of 'javascript check if id exists' in JavaScript

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function hasId(id) {
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    //有此id返回true，否则返回false
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    var element = document.getElementById(id);
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    if (element) {
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        return true
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    } else {
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        return false
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    }
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}

119
function check(idStr){
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    var that = $("#"+idStr)
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    var parent = that.parent()
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    if(that.val().trim()==""){
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        var msg;
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        if(idStr=="name"){
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            msg = "名称不能为空"
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        }
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        that.addClass("is-invalid")
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        if(parent.children("[name='nameError']").length==0){
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            parent.append('<div>'+msg+'</div>')
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        }
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        return false;
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    }else{
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        that.removeClass("is-invalid")
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        parent.children("[name='nameError']").remove();
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        return true
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    }
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}

15
function _validateId(id) {
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  if (id && typeof id !== 'undefined' && parseInt(id) > 0) {
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    return true;
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  }
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  return false;
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}

55
function setIdHasCheck(id, hasCheck) {
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  if (OS_ANDROID) {
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    $[id + 'Check'].visible = hasCheck;
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  } else {
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    $[id].hasCheck = hasCheck;
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  }
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}

205
checkId (id) {
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    if (id in this.players) { return true; }
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    else { return false; }
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}

17
function CheckExists(id) {
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    var idName = "assets/" + id.toLowerCase();
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    var idNoExt = idName.substring(0, idName.lastIndexOf("."));
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    return allFiles.hasOwnProperty(idName) || allAssets.hasOwnProperty(idNoExt);
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}

135
isValidId(id) {
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  return id !== undefined && id !== 0 && id !== ''
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}

1
function jsCheck(id)
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{
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 el=document.getElementById(id);
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 el.checked='checked';
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}

13
function isValid(id) {
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  if (!id || !(typeof id === 'number' || id instanceof Number) && id.length !== 12 && id.length !== 24) {
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    return false;
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  }
17
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  if ((typeof id === 'string' || id instanceof String) && id.length === 24) {
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    return /^[0-9a-fA-F]{24}$/i.test(id);
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  }
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  return true;
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}

15
function getId(id, callback) {
16
  
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  var filename = getFilename(id);
18
  
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  s3.getObject({
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    Bucket: settings.bucket,
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    Key: filename
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  }, function(error, data) {
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    if(error) {
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      if(error.code == 'NoSuchKey') {
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        callback({code:404,msgs:["Not Found"]});
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      } else {
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        callback({code:500,msgs:["S3 Retrieval Error"]});
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      }
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    } else {
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      callback(null,JSON.parse(data.Body));
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    }
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  });
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}