Basic methods of JS array operation

1. Array detection

var newArr = [];newarr  instanceof Array;   // true Array.isarray (NEWARR);   // true // Array.isarray (NEWARR) only supports Ie9+,firefox 4+,safari 5+,opera 10.5+ and Chrome

2. Creating an array

var New // Create an array var New Array (3);  // Create an array and specify the length var New Array (1,2,[3,4]);  //

3. Adding elements

Newarr.push (' A ');  // 6newArr;  // [1,2,3,4,5, ' A '] Newarr.unshift (//7//  [' B ', 1,2,3,4,5, ' A ']newarr.splice (  //  []//["B", 1, "C", 2, 3, 4, 5, "A"]

4. Deleting elements

var newArr = [1,2,3,4,5];newarr.pop ();   // 5newArr;  // [1,2,3,4]  //1newArr;  // [2,3,4] Newarr.splice (//[3,4]newArr;  // [2]

5. Intercepting and merging elements

var newArr = [' A ', ' B ', ' C ', ' d ', ' E '];newarr.slice (//["C", "D", "E"]// ["B", "C", "D"] newarr.concat (' M ');  // ["A", "B", "C", "D", "E", "M"]

6, copy of the array

var newArr = [' A ', ' B ', ' C ', ' D ', ' E '];newarr.slice (//["A", "B", "C", "D", "E"] Newarr.concat ();  // ["A", "B", "C", "D", "E"]

7. Sorting of arrays

var newArr = [' A ', ' C ', ' B ', ' D ', ' M '];newarr.reverse ();   // ["M", "D", "B", "C", "A"]newarr.sort ();  // "A", "B", "C", "D", "M"]

8. String conversion of arrays

var  NEWARR = [];newarr.join (', ');  // "Newarr.tostring"();  // " the" // "newarr.valueof"();  // [A] // tolocalestring, toString, valueOf: Can be seen as a special use of joins, not commonly used

9. Array Lookup

varNEWARR = [1,2,3,4,5,4,3,2,3,4];newarr.indexof (3);//first occurrence of element 3 location: 2Newarr.indexof (3,4);//starting from position 3 Find the first occurrence of element 4 in the location: 6Newarr.lastindexof (3);//last occurrence of element 3 location: 8Newarr.lastindexof (2,4);//starting at position 4 finding the last occurrence of element 2:1varPerson={name: "Lili"}, Person1=[{name: "Lili"}], Person2=[Person];p erson1.indexof (person);//return-1 must be strictly equal, not just value equalPerson2.indexof (person);//returns 0//indexOf () from the go after looking, not found for-1//lastIndexOf () Looking forward from the back, not found for-1

Note: Self-search data collation, for reference only, thank you ~ ~

Basic methods of JS array operation