13-Dark Horse programmer------C language Learning Note---C language one-dimensional array

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Four simple construction data types

One by one-D arrays

Definition of a 11-D array:

Type identifier array name [constant expression]; such as: int a[10]; the expression defines an integer array named a, which has 10 elements, 10 integer variables, which can store 10 integer data.

The 02 type identifier represents the data type of an array element, the array name is a user-defined identifier, and the first address of the memory area that the array occupies, and the constant expression is enclosed in square brackets, whose value represents the number of array elements, that is, the array length.

The C language stipulates that the subscript of an array starts with 0, and if an array with n elements is defined, its elements correspond to the subscript 0~n-1

/*A class of 30 students is known to take the C language exam, requiring programs to be written, input each student's scores, calculate average scores, and output all students ' test scores and average scores*/#include<stdio.h>intMain () {floatcscore[ -]; floatsum=0, average; inti; printf ("Please enter the score of 30 students: \ n");  for(i=0; i< -; i++) {printf ("grade%d student results \ n", i+1); scanf ("%f",&Cscore[i]); Sum= sum+Cscore[i]; } Average= sum/ -;  for(i=0; i< -; i++) {printf ("score of%d:%f\n", i+1, Cscore[i]); printf ("average=%f\n", average); }        return 0; }

04 The reference form of an array element:

Array name [subscript]

When referencing, the subscript can be an integer constant, or it can be an integer variable or an integer expression that is assigned a value.

The C language allows you to specify an initial value for each element when the array is defined, called the initialization of the array.

such as: int a[10]={0,1,2,3,4,5,6,7,8,9};

You can also assign values to only a subset of the array elements, the system assigns the default values to the rest of the elements, and when the elements are numeric data, the default is 0, and the character data defaults to ' \ n ',

/*prompts the user to enter 5 students ' scores, calculates the average score and outputs*/#include<stdio.h>voidtest ();intMain () {intscore[5]; intsum =0;  for(inti =1; i<=5; i++) {printf ("Please enter the score of%d students: \ n", i); scanf ("%d", &score[i-1]); Sum+ = score[i-1]; } printf ("average is%f\n", sum/5.0);        Test (); return 0; }voidTest () {intAges[] = {4, -, +};  for(inti =1; i<=3; i++) {printf ("ages[%d] 's address is%p\n", I-1, &ages[i-1]); }                                    }

06 Assign values to all array elements, without specifying the length of the array, whose length is determined automatically by the number of initial values

07 arrays can only be assigned when initialized, and cannot be assigned as a whole when used

/*int count = 5;int Ages[count];ages[0] = 1;ages[1] = 6;ages[2] = 8;//error notation//If you want to initialize at the same time as the array is defined, the number of elements in the array must be constant or not write/int AG Es[count] = {10,11,12};*/#include<stdio.h>intMain () {intages[]={Ten,4,5,8, +,}; intCount = (sizeof(ages)) /sizeof(int);  for(inti =0; i<count; i++) {printf ("ages[%d]=%d\n", I,ages[i]); }        return 0; 

13-Dark Horse programmer------C language Learning Note---C language one-dimensional array