Decoupling assignment of strings (detailed explanation)

One of the great advantages of an excellent person is: perseverance in the face of disadvantages and difficulties. -Beethoven

Determine whether the current string contains another given substring

ES5 whether the method comprising providing a
string.indexOf (searchStr) Method
* action - Returns the index containing the specified value specified string matching substring
* Results -
* comprising - Returns the index matching values
* not Contains-returns -1

console.log(str.indexOf('we', 3)); //5 //从指定位置开始往后查找
console.log(str.indexOf('we'));//1 //从整个字符串中查找

ES6 provides whether to include the method
includes () method

console.log(str.includes('we')); //true//从整个字符串中查找
console.log(str.includes('we', 3)); //true//从指定位置开始往后查找

Determine whether the current string "ends" with another given substring

endswidth() method

Determine whether the end of the string with the index value as the termination point, the return value is Boolean

let str = 'swedrwefweda';
console.log(str.endsWith('da')); //true
console.log(str.endsWith('swe', 3)); //true

Determine whether the current string is "given" by another given substring

startswidth() method

Does not mean that the specified string starts with another string
Indicates whether the specified index value of the specified string starts with another string
Judge whether the string starts with the specified index value. If yes, return true, otherwise false

let str = 'swedrwefweda';
console.log(str.startsWith('sw')); //true
console.log(str.startsWith('dr', 3)); //false

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The above methods are all case-sensitive.
Because you are very likely to encounter in your work you don’t want her to be case-sensitive, so I wrote an example (make it case-insensitive)
so that you can work Efficiency a little bit faster

let str = 'swedrwefweda';
Object.defineProperty(String.prototype, 'myIncludes', {
    value: function (searchStr, index) {
        let str = this.toLowerCase();
        searchStr = searchStr.toLowerCase();
        if (typeof index === 'number') {
            return str.includes(searchStr, index);
        } else {
            return str.includes(searchStr);
        }
    }
});
console.log(str.myIncludes('we', 3))

I hope you can accumulate a little bit of progress in your work

Today's golden sentence

If you don't accumulate steps, you can't reach a thousand miles; if you don't accumulate small currents, you can't become a river.