js數組都有哪些方法


//數組的方法     toString(),join(),pop(),push(),shift(),unshift(),splice(),concat(),slice() 
        //1.toString()與join()一樣都是把數組轉成以逗號分割的字符串
        var fruits=['Banana','Orange','Apple'];
        var foods=['rice']
        console.log(fruits.toString()) // Banana,Orange,Apple
        console.log(fruits.join()) // Banana,Orange,Apple


        //2.pop() 刪除數組的最后一項
        var fruits=['Banana','Orange','Apple'];
        var str=fruits.pop(); //str=Apple
        console.log(fruits) //['Banana','Orange']
        //3.push() 往數組最后添加新數據
        var fruits=['Banana','Orange','Apple'];
        var str=fruits.push('kkk') // str=4 返回的數組的長度        
        console.log(fruits) //['Banana','Orange','Apple','kkk'];    
        
        //4.shift() 刪除數組最前面的一項
        var fruits = ["Banana", "Orange", "Apple", "Mango"];
        var str=fruits.shift();   //str=Banana
        console.log(fruits) //["Orange", "Apple", "Mango"];    
        //5. unshift() 往數組開頭添加新數據
        var fruits = ["Banana", "Orange", "Apple", "Mango"];
        var str=fruits.unshift('ll');   //str=ll
        console.log(fruits) //["ll", "Banana", "Orange", "Apple", "Mango"]
        //6. splice() 方法可用於向數組添加新項或者刪除數組
        //新增
        var fruits = ["Banana", "Orange", "Apple", "Mango"];
        fruits.splice(2, 0, "Lemon", "Kiwi");
        console.log( fruits)// ["Banana", "Orange", "Lemon", "Kiwi", "Apple", "Mango"]
         //刪除
        var fruits = ["Banana", "Orange", "Apple", "Mango"];
        fruits.splice(2, 1);
        console.log(fruits)// ["Banana", "Orange", "Mango"]
        //7.concat()連接兩個數組生成一個新數組
        var fruits= ["Banana", "Orange", "Mango"];
        var fruits1=['222'];
        console.log(fruits.concat(fruits1)) //["Banana", "Orange", "Mango", "222"]
        //8.slice()  
        var fruits = ["Banana", "Orange", "Lemon", "Apple", "Mango"];
        var citrus = fruits.slice(1); 
        console.log(citrus) // (4) ["Orange", "Lemon", "Apple", "Mango"]

 


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