To fix this, we can check whether the user has entered any text into the input before wetrimit. input.addEventListener('input',evt=>{constvalue=input.valueif(!value) {input.dataset.state=''return}consttrimmed=value.trim()if(trimmed) {input.dataset.state='valid'}else{input.dataset.state='...
1、function checked(){ var isChecked = false; $("input[@type=checkbox]").each( function(){ if($(this).attr("checked")){ isChecked=true; return; } }) if(!isChecked){ alert("请至少选择一条记录进行操作!"); } return isChecked; } 2、funcion checked2{ var isChecked=$("id").at...
Once again, this method will fail on anullorundefinedinput. 3.JSON.stringify TheJSON.stringifymethod is used to convert a JavaScript object to a JSON string. So we can use it to convert an object to a string, and we can compare the result with{}to check if the given object is empty...
},// 非常基本的方法myMethod:function () {console.log("Where in the world is Paul Irish today?" ); },// 输出基于当前配置configuration的一个值myMethod2:function () {console.log("Caching is:" + (this.myConfig.useCaching ) ?"enabled" :"disabled" ); },// 重写当前的配置(configuration)...
writeToLog("Input : " + str1); 5. writeToLog("From position 6: " + str2); 6. writeToLog("From position 6 for 7 long : " + str3); 1. 2. 3. 4. 5. 6. 控制台输出如下: 1. 2019/08/19 13:31:20 - JavaScript代码.0 - Input : Hello Pentaho! 2. 2019/08/19 13:31:...
("Caching is:"+(this.myConfig.useCaching)?"enabled":"disabled");},// 重写当前的配置(configuration)myMethod3:function(newConfig){if(typeofnewConfig==="object"){this.myConfig=newConfig;console.log(this.myConfig.language);}}};myModule.myMethod();// Where in the world is Paul Irish ...
writeToLog("Input : " + str1); writeToLog("Index of 'Pentaho' : " + str2); writeToLog("index of 'o', search from position 7 : " + str3); 最终控制台输出: 2019/08/19 10:34:16 - JavaScript代码.0 - Input : Hello Pentaho!
Write a JavaScript function to check whether an 'input' is an array or not. Test Data: console.log(is_array('w3resource')); console.log(is_array([1, 2, 4, 0])); false true Sample Solution: JavaScript Code: // Function to check if the input is an arrayvaris_array=function(input...
For instance - imagine you made a typo, and accidentally input somevariable instead of someVariable in the if clause: let someVariable = 'Hello!' if (typeof somevariable === 'undefined') { console.log('Undefined variable'); } else if (typeof somevariable === 'null') { console.log(...
You walk through one line at a time to help you figure out exactly where your code is running in a different order than you expect. Try it now:Click Step over next function call (). DevTools runs the following code without stepping into it: JavaScript 複製 if (inputsAreEmpty()) { ...